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1.
Phys Rev Lett ; 131(5): 051801, 2023 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-37595210

RESUMO

MINERvA has measured the ν_{µ}-induced coherent π^{+} cross section simultaneously in hydrocarbon (CH), graphite (C), iron (Fe), and lead (Pb) targets using neutrinos from 2 to 20 GeV. The measurements exceed the predictions of the Rein-Sehgal and Berger-Sehgal PCAC based models at multi-GeV ν_{µ} energies and at produced π^{+} energies and angles, E_{π}>1 GeV and θ_{π}<10°. Measurements of the cross-section ratios of Fe and Pb relative to CH reveal the effective A scaling to increase from an approximate A^{1/3} scaling at few GeV to an A^{2/3} scaling for E_{ν}>10 GeV.

2.
Phys Rev Lett ; 131(1): 011801, 2023 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-37478458

RESUMO

Neutrino-induced charged-current single π^{+} production in the Δ(1232) resonance region is of considerable interest to accelerator-based neutrino oscillation experiments. In this Letter, high statistic differential cross sections are reported for the semiexclusive reaction ν_{µ}A→µ^{-}π^{+}+ nucleon(s) on scintillator, carbon, water, iron, and lead targets recorded by MINERvA using a wideband ν_{µ} beam with ⟨E_{ν}⟩≈6 GeV. Suppression of the cross section at low Q^{2} and enhancement of low T_{π} are observed in both light and heavy nuclear targets compared with phenomenological models used in current neutrino interaction generators. The cross sections per nucleon for iron and lead compared with CH across the kinematic variables probed are 0.8 and 0.5 respectively, a scaling which is also not predicted by current generators.

3.
Phys Rev Lett ; 130(16): 161801, 2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37154647

RESUMO

This Letter presents the first simultaneous measurement of the quasielasticlike neutrino-nucleus cross sections on C, water, Fe, Pb, and scintillator (hydrocarbon or CH) as a function of longitudinal and transverse muon momentum. The ratio of cross sections per nucleon between Pb and CH is always above unity and has a characteristic shape as a function of transverse muon momentum that evolves slowly as a function of longitudinal muon momentum. The ratio is constant versus longitudinal momentum within uncertainties above a longitudinal momentum of 4.5 GeV/c. The cross section ratios to CH for C, water, and Fe remain roughly constant with increasing longitudinal momentum, and the ratios between water or C to CH do not have any significant deviation from unity. Both the overall cross section level and the shape for Pb and Fe as a function of transverse muon momentum are not reproduced by current neutrino event generators. These measurements provide a direct test of nuclear effects in quasielasticlike interactions, which are major contributors to long-baseline neutrino oscillation data samples.

4.
Nature ; 614(7946): 48-53, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36725994

RESUMO

Scattering of high energy particles from nucleons probes their structure, as was done in the experiments that established the non-zero size of the proton using electron beams1. The use of charged leptons as scattering probes enables measuring the distribution of electric charges, which is encoded in the vector form factors of the nucleon2. Scattering weakly interacting neutrinos gives the opportunity to measure both vector and axial vector form factors of the nucleon, providing an additional, complementary probe of their structure. The nucleon transition axial form factor, FA, can be measured from neutrino scattering from free nucleons, νµn → µ-p and [Formula: see text], as a function of the negative four-momentum transfer squared (Q2). Up to now, FA(Q2) has been extracted from the bound nucleons in neutrino-deuterium scattering3-9, which requires uncertain nuclear corrections10. Here we report the first high-statistics measurement, to our knowledge, of the [Formula: see text] cross-section from the hydrogen atom, using the plastic scintillator target of the MINERvA11 experiment, extracting FA from free proton targets and measuring the nucleon axial charge radius, rA, to be 0.73 ± 0.17 fm. The antineutrino-hydrogen scattering presented here can access the axial form factor without the need for nuclear theory corrections, and enables direct comparisons with the increasingly precise lattice quantum chromodynamics computations12-15. Finally, the tools developed for this analysis and the result presented are substantial advancements in our capabilities to understand the nucleon structure in the weak sector, and also help the current and future neutrino oscillation experiments16-20 to better constrain neutrino interaction models.

5.
Phys Rev Lett ; 129(2): 021803, 2022 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-35867435

RESUMO

Neutrino charged-current quasielastic-like scattering, a reaction category extensively used in neutrino oscillation measurements, probes nuclear effects that govern neutrino-nucleus interactions. This Letter reports the first measurement of the triple-differential cross section for ν_{µ} quasielastic-like reactions using the hydrocarbon medium of the MINERvA detector exposed to a wideband beam spanning 2≤E_{ν}≤20 GeV. The measurement maps the correlations among transverse and longitudinal muon momenta and summed proton kinetic energies, and compares them to predictions from a state-of-art simulation. Discrepancies are observed that likely reflect shortfalls with modeling of pion and nucleon intranuclear scattering and/or spectator nucleon ejection from struck nuclei. The separate determination of leptonic and hadronic variables can inform experimental approaches to neutrino-energy estimation.

6.
J Med Vasc ; 45(4): 192-197, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32571559

RESUMO

OBJECTIVE: Numerous guidelines have been published on the management of venous thromboembolism (VTE). However, therapeutic decision-making may prove challenging in routine clinical practice. With this in mind, multidisciplinary team (MDT) meetings have been set up in Rennes University Hospital, France. This study sought to describe the situations discussed during MDT meetings and to assess whether the meetings bring about changes in the management of these patients. MATERIALS AND METHODS: A retrospective single-center study conducted at the Rennes University Hospital included cases presented from the beginning of the MDT meetings (February 2015) up to May 2017. RESULTS: In total, 142 cases were presented in 15 MDT meetings, corresponding to a mean of 10±4 cases per meeting. Of these, 129 related to VTE patients: 33 provoked VTEs, 22 unprovoked VTEs, 49 cancer-related VTEs, and 25 unspecified VTEs. MDT meetings led to significant changes in the anticoagulation type (therapeutic, prophylactic, or discontinuation) and duration, but not in the anticoagulant choice (direct oral anticoagulants, vitamin K antagonists, heparins, etc.). CONCLUSION: Requests for MDT meetings are made for all VTE types, and these meetings have an impact on VTE management.


Assuntos
Anticoagulantes/administração & dosagem , Coagulação Sanguínea/efeitos dos fármacos , Tomada de Decisão Clínica , Comportamento Cooperativo , Comunicação Interdisciplinar , Equipe de Assistência ao Paciente , Tromboembolia Venosa/tratamento farmacológico , Administração Oral , Anticoagulantes/efeitos adversos , Esquema de Medicação , França , Hospitais Universitários , Humanos , Seleção de Pacientes , Estudos Retrospectivos , Resultado do Tratamento , Tromboembolia Venosa/diagnóstico , Tromboembolia Venosa/etiologia
7.
J Med Vasc ; 44(5): 331-335, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31474343

RESUMO

OBJECTIVES: Cardiovascular diseases represent the leading cause of death worldwide. In a previous survey, we have shown that the management of patients with atherosclerosis by general practitioners depends on the locations of the disease. The aim of this survey was to assess general practice residents' (GPR) knowledge on three clinical presentations which are ischemic stroke, coronary artery disease (CAD), and peripheral artery disease (PAD). MATERIALS AND METHODS: Between May 2017 and September 2017, a national self-administered survey that we previously used to assess the GPs' knowledge was emailed to GPRs from French medicine faculties. The questionnaire was composed of three clinical cases dealing with transient ischemic attack (TIA), stable angina (SA) and intermittent claudication (IC). Each clinical case was explored by seven similar questions. The primary endpoint was the number of GPRs who correctly answered 5 of the 7 questions for each clinical case. RESULTS: Five hundred and fifty-three GPRs (10%) answered the questionnaire entirely. There is a significant difference between TIA knowledge (19.9% of correct answers) which is greater than SA knowledge (0.9%) and IC knowledge (0.4%). The diagnosis was correctly done by 525 (94.9%) GPRs for TIA, 513 (92.8%) for SA, and 532 (96.2%) for IC. The main difficulties encountered by the GPRs concerned complementary investigations and treatment. CONCLUSION: As for general practitioners, this study reveals a difference in GPRs' knowledge depending on the location of the atherosclerosis. Considering the results, the improvement of initial training and continuing medical education (CME) in general medicine would be desirable.


Assuntos
Aterosclerose/diagnóstico , Aterosclerose/terapia , Educação de Pós-Graduação em Medicina , Medicina Geral/educação , Conhecimentos, Atitudes e Prática em Saúde , Internato e Residência , Atenção Primária à Saúde , Angina Estável/diagnóstico , Angina Estável/terapia , Atitude do Pessoal de Saúde , Competência Clínica , Currículo , Pesquisas sobre Atenção à Saúde , Humanos , Claudicação Intermitente/diagnóstico , Claudicação Intermitente/terapia , Ataque Isquêmico Transitório/diagnóstico , Ataque Isquêmico Transitório/terapia
8.
Phys Rev Lett ; 123(4): 042502, 2019 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-31491269

RESUMO

We report the first measurement of the neutron cross section on argon in the energy range of 100-800 MeV. The measurement was obtained with a 4.3-h exposure of the Mini-CAPTAIN detector to the WNR/LANSCE beam at LANL. The total cross section is measured from the attenuation coefficient of the neutron flux as it traverses the liquid argon volume. A set of 2631 candidate interactions is divided in bins of the neutron kinetic energy calculated from time-of-flight measurements. These interactions are reconstructed with custom-made algorithms specifically designed for the data in a time projection chamber the size of the Mini-CAPTAIN detector. The energy averaged cross section is 0.91±0.10(stat)±0.09(syst) b. A comparison of the measured cross section is made to the GEANT4 and FLUKA event generator packages, where the energy averaged cross sections in this range are 0.60 and 0.68 b, respectively.

9.
Philos Trans A Math Phys Eng Sci ; 377(2137)2018 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-30530544

RESUMO

The dome of Santa Maria del Fiore, Florence Cathedral, was built between 1420 and 1436 by architect Filippo Brunelleschi and it is now cracking under its own weight. Engineering efforts are under way to model the dome's structure and reinforce it against further deterioration. According to some scholars, Brunelleschi might have built reinforcement structures into the dome itself; however, the only known reinforcement is a wood chain 7.75 m above the springing of the Cupola. Multiple scattering muon radiography is a non-destructive imaging method that can be used to image the interior of the dome's wall and therefore ascertain the layout and status of any iron substructure in it. A demonstration measurement was performed at the Los Alamos National Laboratory on a mock-up wall to show the feasibility of the work proposed, and a lightweight and modular imaging system is currently under construction. We will discuss here the results of the demonstration measurement and the potential of the proposed technique, describe the imaging system under construction and outline the plans for the measurement.This article is part of the Theo Murphy meeting issue 'Cosmic-ray muography'.

10.
Annu Int Conf IEEE Eng Med Biol Soc ; 2018: 596-599, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30440467

RESUMO

In this paper, we present a new diffeomorphic registration algorithm for the registration of 3D models to 3D points. A biventricular template is iteratively fitted to the data by a series of implicitly constrained diffeomorphic linear least squares fits with decreasing regularization weights before performing an explicitly constrained diffeomorphic fit. The algorithm has been tested on a set of manual contours from 20 patients with a variety of congenital heart disease. Registration accuracy was assessed by calculating the mean point-to-point distance and the Dice overlap metric. Results showed that the method was able to accurately fit the biventricular model to 3D points and that the deformable model was able to fit all the pathologies while being diffeomorphic. The algorithm took approximately 5 minutes to fit each case, with an average of 52,580 points per case.


Assuntos
Algoritmos , Cardiopatias/congênito , Cardiopatias/diagnóstico , Modelos Cardiovasculares , Humanos
11.
Artigo em Inglês | MEDLINE | ID: mdl-25122389

RESUMO

We study numerically joint mixing of salt and colloids by chaotic advection and how salt inhomogeneities accelerate or delay colloid mixing by inducing a velocity drift V(dp) between colloids and fluid particles as proposed in recent experiments [J. Deseigne et al., Soft Matter 10, 4795 (2014)]. We demonstrate that because the drift velocity is no longer divergence free, small variations to the total velocity field drastically affect the evolution of colloid variance σ(2) = 〈C(2)〉-〈C〉(2). A consequence is that mixing strongly depends on the mutual coherence between colloid and salt concentration fields, the short time evolution of scalar variance being governed by a new variance production term P = -〈C(2)∇ · V(dp)〉/2 when scalar gradients are not developed yet so that dissipation is weak. Depending on initial conditions, mixing is then delayed or enhanced, and it is possible to find examples for which the two regimes (fast mixing followed by slow mixing) are observed consecutively when the variance source term reverses its sign. This is indeed the case for localized patches modeled as Gaussian concentration profiles.


Assuntos
Movimento (Física) , Dinâmica não Linear , Sais , Coloides , Cinética
12.
Phys Rev Lett ; 105(18): 181801, 2010 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-21231096

RESUMO

The MiniBooNE experiment at Fermilab reports results from a search for ¯ν_{µ}→¯ν_{e} oscillations, using a data sample corresponding to 5.66×10²° protons on target. An excess of 20.9±14.0 events is observed in the energy range 475

13.
Phys Rev Lett ; 103(11): 111801, 2009 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-19792365

RESUMO

The MiniBooNE Collaboration reports initial results from a search for nu(mu)-->nu(e) oscillations. A signal-blind analysis was performed using a data sample corresponding to 3.39x10(20) protons on target. The data are consistent with background prediction across the full range of neutrino energy reconstructed assuming quasielastic scattering, 200

14.
Phys Rev Lett ; 103(6): 061802, 2009 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-19792551

RESUMO

The MiniBooNE Collaboration reports a search for nu_{micro} and nu[over]_{micro} disappearance in the Deltam;{2} region of 0.5-40 eV;{2}. These measurements are important for constraining models with extra types of neutrinos, extra dimensions, and CPT violation. Fits to the shape of the nu_{micro} and nu[over]_{micro} energy spectra reveal no evidence for disappearance at the 90% confidence level (C.L.) in either mode. The test of nu[over]_{micro} disappearance probes a region below Deltam;{2} = 40 eV;{2} never explored before.

15.
Phys Rev Lett ; 90(4): 041801, 2003 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-12570410

RESUMO

The K2K experiment observes indications of neutrino oscillation: a reduction of nu(mu) flux together with a distortion of the energy spectrum. Fifty-six beam neutrino events are observed in Super-Kamiokande (SK), 250 km from the neutrino production point, with an expectation of 80.1(+6.2)(-5.4). Twenty-nine one ring mu-like events are used to reconstruct the neutrino energy spectrum, which is better matched to the expected spectrum with neutrino oscillation than without. The probability that the observed flux at SK is explained by statistical fluctuation without neutrino oscillation is less than 1%.

17.
Hum Genet ; 105(5): 410-7, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10598805

RESUMO

Autosomal dominant cerebellar ataxia with retinal degeneration (ADCA type II) is a progressive neurodegenerative disorder caused by a CAG expansion in the spinocerebellar ataxia 7 (SCA7) gene. Here, we describe the genomic organisation of the human SCA7 gene. The exon-intron boundaries were identified by sequencing plasmid subclones of a P1 artificial chromosome (PAC) clone containing the entire SCA7 gene. We found 13 exons, ranging in size from 69 to 979 bp, with all exon-intron boundaries following the GT-AG rule. The ATG initiation codon at position 554 of the cDNA occurs in exon 3 at position 12 and the coding region extends to the first five codons of exon 13, with the CAG repeat being located in exon 3 starting at codon 30. The intron sizes were determined by long-distance polymerase chain reaction with primers from neighbouring exons and by restriction mapping of the SCA7 PAC clone. The introns varied in size from 233 bp to about 40 kb, resulting in an overall size estimate for the SCA7 gene of 140 kb. Sequence analysis of intron 7 (491 bp) revealed a polymorphic GT/AC repeat, a useful intragenic marker for SCA7 in segregation studies.


Assuntos
Genes Dominantes , Degeneração Retiniana/genética , Ataxias Espinocerebelares/genética , Sequência de Bases , Primers do DNA/genética , Éxons , Humanos , Íntrons , Repetições Minissatélites , Dados de Sequência Molecular , Splicing de RNA/genética , Mapeamento por Restrição , Ataxias Espinocerebelares/classificação , Repetições de Trinucleotídeos
18.
Brain Res Mol Brain Res ; 74(1-2): 35-43, 1999 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-10640674

RESUMO

Autosomal dominant cerebellar ataxias (ADCAs) are a complex group of neurodegenerative disorders characterized by progressive degeneration of the cerebellum, brain stem and spinal cord. The spinocerebellar ataxia type 7 (SCA7) is associated with pigmentary macular dystrophy and retinal degeneration leading to blindness caused by a CAG/polyglutamine (polyGln) expansion in the coding region of the SCA7 gene/protein. The SCA7 gene codes for ataxin-7, a protein of unknown function. To investigate its cellular and subcellular localization, we have developed a sequence-specific polyclonal antibody against the N-terminal part of the protein. Immunohistochemical analysis indicated that ataxin-7 accumulates as single nuclear inclusion (NI) in the cells of the brain and retina of a SCA7 patient but not of controls. The 1C2 antibody, directed against expanded polyGln, confirmed the aggregation of mutant ataxin-7 in these NIs. Furthermore, ubiquitin was found in these aggregates, suggesting that mutant ataxin-7 is a target for ubiquitin-dependent proteolysis, but resistant to removal. Electron microscopic studies using immunogold labeling showed that ataxin-7 immunoreactive NIs appear as dense aggregates containing a mixture of granular and filamentary structures. Together, these data confirm the presence of NIs in brain and retina of a SCA7 patient, a common characteristic of disorders caused by expanded CAG/polyGln repeats.


Assuntos
Ataxia Cerebelar/metabolismo , Proteínas do Tecido Nervoso/análise , Ponte/química , Retina/química , Adulto , Anticorpos Monoclonais/imunologia , Especificidade de Anticorpos , Ataxina-7 , Química Encefálica , Ataxia Cerebelar/imunologia , Ataxia Cerebelar/patologia , Pré-Escolar , Evolução Fatal , Feminino , Humanos , Imuno-Histoquímica , Masculino , Microscopia Imunoeletrônica , Pessoa de Meia-Idade , Proteínas do Tecido Nervoso/imunologia , Retina/ultraestrutura
19.
Eur J Neurosci ; 10(2): 529-37, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9749715

RESUMO

Polyclonal antibodies against the mouse D4 dopamine receptor have been developed in order to investigate the anatomical localization of this receptor in the mouse brain. Two antibodies were generated against specific peptides corresponding to predicted extracellular and intracellular regions of the D4 protein. Specificity of these antibodies was demonstrated on human embryonic kidney 293 (HEK 293) cells transfected with different dopamine receptor subtypes; immunoreactivity was detected only in cells transfected with the mouse D4 dopamine receptor cDNA. Following in vitro transcription/translation of the mouse D4 cDNA, a single protein band of 36 kDa was selectively immunoprecipitated with the anti-D4 antibodies. The antibodies also detected a single protein of 36 kDa in Western blot of HEK 293 cells transiently transfected with the mouse D4 receptor. These antibodies were able to detect the D4 receptor in several regions of the mouse brain. In the regions examined, D4 immunoreactivity was found in neurones located in layers II-VI of the frontal and piriform cortices, with the highest concentration in layer II; in scattered neurones in the caudate putamen and in larger neurones in the globus pallidus. In all experiments, both antibodies exhibit the same specificity, and all immunoreactivity could be abolished by preincubation with the corresponding peptide antigen.


Assuntos
Anticorpos Bloqueadores/farmacologia , Antagonistas dos Receptores de Dopamina D2 , Sequência de Aminoácidos , Animais , Anticorpos Bloqueadores/química , Anticorpos Bloqueadores/imunologia , Western Blotting , Linhagem Celular , Imunofluorescência , Humanos , Camundongos , Conformação Molecular , Dados de Sequência Molecular , Testes de Precipitina , Receptores de Dopamina D2/imunologia , Receptores de Dopamina D4 , Fixação de Tecidos
20.
J Immunol ; 156(6): 2247-55, 1996 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-8690915

RESUMO

Astrocytes express C components and have been implicated as a major source of intrathecal C. To ascertain the effects of C activation on these cells, we have evaluated the expression of CR1, CR2, and CR3 (CD35, CD21, and CD11b/CD18) in primary fetal astrocytes and astrocyte cell lines. None of the astrocyte cells tested expressed CR3, whereas primary astrocytes and one of four astrocyte cell lines expressed CR1 (220 kDa), as assessed at the protein and mRNA level. Primary fetal astrocytes and all four astrocyte cell lines expressed CR2 (155 kDa). Expression of CR2 by astrocytes was confirmed at mRNA level by reverse-transcriptase PCR, using different combinations of seven specific CR2 oligonucleotides, and by partial sequencing of the astrocyte CR2 cDNA. Astrocyte CR2 cDNA presented 100% homology with the lymphocyte CR2 cDNA between the position 181 bp to 600 bp and position 1017 bp to 1347 bp. An alternative splicing pattern of exon 11, reported previously in B cells, was observed in astrocyte CR2 cDNA. Astrocyte CR2 was functional, in that it specifically bound C3d and the EBV surface protein gp340, and the binding was blocked specifically with polyclonal anti-CR2. Scatchard analysis of membrane expression of CR2 on astrocytes revealed 2000 functional sites per cell with a Kd (3 x 10(-7) M) identical with that of CR2 on B cell (Raji).


Assuntos
Astrócitos/química , Complemento C3/química , Receptores de Complemento/química , Astrócitos/imunologia , Astrócitos/metabolismo , Sequência de Bases , Linhagem Celular , Complemento C3d/metabolismo , Feto , Herpesvirus Humano 4/metabolismo , Humanos , Ligantes , Antígeno de Macrófago 1/análise , Dados de Sequência Molecular , Ligação Proteica/imunologia , Receptores de Complemento 3b/análise , Receptores de Complemento 3d/análise
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